Parcasious is a Fanfic writer most known of writing Shirou Emiya into another world.
They have written fanfics for Fate Series, Naruto, RWBY, Fairy Tail, Lyrical Nanoha, High School D×D, Campione!, Overlord (2012), Food Wars!, Bleach, Akame ga Kill!, The Rising of the Shield Hero, Gate, Is It Wrong to Try to Pick Up Girls in a Dungeon?, Dragon Ball Z, and Hellsing.
You can find them on FF.Net and Ao3